The present invention relates to airfoil repair methods and apparatuses, and more particularly to methods and apparatuses for airfoil chord repairs that involve restoring radiused leading and trailing edges.
Gas turbine engines utilize airfoils, including compressor stators (or vanes), that interact with fluid flows through the engine. During use, those airfoils can become worn or damaged. For instance, it is common for wear or damage at leading and trailing edges of airfoils to occur. Worn or damaged airfoils can be replaced in order to keep the engine in service. Alternatively, the worn or damaged airfoils can be repaired to keep the original airfoils in service in the engine, which can provide significant cost savings over the use of replacement parts.
A known repair for airfoil leading and trailing edges involves removing parent material of the airfoil at the location of the damage or wear, adding filler material to replace the removed parent material, performing a coining (or forging) operation on the filler material, and then machining the coined filler material to original blueprint dimensions. However, this known repair method has drawbacks. For instance, in order to machine leading and trailing edges to original blueprint dimensions, a relatively expensive robotic adaptive blending machine is typically required, such as a 5-axis computer numeric controlled (CNC) automated blending machine with a vision system that can cost on the order of $1 million U.S. dollars.
Vibratory finishing processes are known for processing edges of airfoils using a media placed in a vibration bowl with the airfoil. However, these known vibratory finishing processes are primarily for polishing, and may be inadequate, or at a minimum inefficient, for restoring airfoil edges following a coining operation.